This application claims the priority of French application FR/01.02620, filed Feb. 27, 2001, the entire disclosure of which is incorporated herein by reference.
1. Technical Field
The invention relates to the field of sports involving gliding over snow. It relates more particularly to a device, mounted on a board, which is arranged in order to allow the adaptation of the stiffness of the board as a function of the user""s wishes. In the remainder of the description, the invention is more specifically described in its use on an alpine ski, but it could also be applied to snowboards.
2. Prior Art
In a known manner, alpine skis may be equipped with stiffening devices and/or with platforms for raising the binding. A stiffening device is generally formed by a rigid plate anchored on the board at at least two distant points, so that its inherent rigidity is added to that of the board. Such devices, like those described in documents FR 2 534 480 and EP 0 183 586, must of necessity be determined as a function of the intrinsic mechanical properties of the board, and their positioning is particularly sensitive.
Also known are other types of accessory fitted on skis, such as platforms for raising the binding. This type of platform makes it possible, on the one hand, to raise the binding relative to the level of the ski and, on the other hand, to eliminate the influence of the ski boot""s stiffness on the intrinsic stiffness of the ski.
Different types of platforms have already been described. The example of such a platform is described in document U.S. Pat. No. 4,896,895. Such a platform consists essentially of a metal plate to which the front stop and the heelpiece of the safety bindings are secured. This metal plate rests on an elastomer layer and is anchored on the board at its two ends, front and rear. One of these ends includes an oblong hole allowing a slight sliding of the platform relative to the board. This device allows damping of some of the vibrations generated on the board and also restriction of the influence of the stiffness of the user""s boot relative to that of the board. Such a platform, by obtaining a certain decoupling of the board, has a very small effect on the board""s stiffness.
In document EP 1 166 834, the applicant has described a platform for raising the binding which is anchored on the board at three different longitudinal levels. Such a platform, which includes distant anchoring zones, ensures significant coupling of the board when its inherent stiffness is added to that of the board. This type of platform is thus particularly intended for competition or more sports-style skiing, for which it is necessary for the board to have significant stiffness.
It thus appears that the various existing types of platform or stiffener are each more specifically intended for one type of skiing. This therefore obliges manufacturers to design and to produce different skis, depending on their ultimate use. This disadvantage for the manufacturer is combined with a drawback for the ski user or retailer, who has to choose a type of platform or stiffener as a function of the intended skiing style and who has to change it if he wishes to adopt a different style.
In patent application FR 00.14032, which was not published as of the date of filing of the present application, the applicant has already described a raising platform for fitting on a ski, and one end of which has the ability to slide longitudinally relative to the board. This sliding capability is obtained by virtue of an elongate aperture located at one end of the platform.
Inside this elongate aperture passes a fixing screw, the head of which may thus be displaced inside the aperture when the platform is displaced slightly relative to the board. It is possible to allow or prevent this sliding by arranging, inside this elongate aperture, an additional piece which, when present, prevents the movement of the screw inside the aperture and thus blocks sliding.
The use of this additional piece requires the user""s intervention, which may be impractical, particularly when the modification is carried out on the snow. Moreover, there is a risk of one of the pieces of the system becoming lost.
Document DE 197 18 860 described another device for fitting on a board for gliding and capable of modifying the stiffness of the board in accordance with an adjustment made by the user. More precisely, this device essentially comprises a platform, the rear end of which has the ability to slide relative to the upper face of the board. This device also includes a movable lever articulated relative to the upper face of the board. A portion of this lever is at the same vertical level as the rear end of the platform and can serve as a stop in order to block the sliding movement of the platform relative to the board. As a function of the position of the lever, this stop effect intervenes at a reasonably early stage during bending of the board.
This device presents a number of drawbacks: it has a complex shape and a multitude of pieces which make it relatively fragile. Moreover, on account of its architecture, this device is the seat of significant mechanical stresses since, irrespective of the position of the articulated lever, the latter undergoes major stresses when it receives the contact of the rear part of the platform.
The invention thus proposes providing a raising platform, the influence of which on the stiffness of the board can be reconfigured at any time by the user, with ease.
The invention thus relates to a platform for raising the binding intended for fitting on a board for gliding, one free end of which has the ability to slide longitudinally relative to the board.
According to the invention, this platform is defined in that it also includes:
a stud intended for securing to the board in order to form a fixed point;
a movable member capable of being displaced within the free end of the platform and through the action of the user, said movable member being able to adopt two positions, namely,
a xe2x80x9cblockedxe2x80x9d position in which it has a portion abutting against the fixed stud, so as to prevent the movement of the free end of the platform relative to the stud;
a xe2x80x9cfreexe2x80x9d position in which it can slide freely relative to the stud and thus allow the longitudinal sliding of the platform relative to the stud.
In other words, the region of the platform which has the ability to slide relative to the board may be blocked in a fixed position relative to the board through the action of the user, who modifies the position of the movable member so that the latter may or may not interact with the stud that is fixed relative to the board.
Thus, when the movable member is in the blocked position, the said member interacts with the fixed stud so as to prevent the displacement of the end of the platform. The platform thus adds its stiffness to that of the board. Conversely, when the movable member is in the xe2x80x9cfreexe2x80x9d position, it does not interfere with the fixed stud during the sliding of the platform. The stiffness of the platform thus has only a very limited influence on the overall stiffness of the board.
In practice, the movable member may be displaced relative to the platform either by means of pivoting or by means of translation.
In a particular embodiment, when the movable member is in the blocked position, the portion abutting against the stud is directed against the end of the platform so as to prevent the sliding of the latter in the direction oriented toward its end. In other words, when it is the rear end of the platform that has the ability to slide, the movable member is in abutment relative to the front face of the stud, so as to prevent the rear end of the platform moving back.
Conversely, if is the front end which has the ability to slide, it will be preferred for the sliding member to be in abutment with the rear face of the fixed stud, to prevent sliding of the platform toward the front of the ski.
In a particular embodiment, the movable member may comprise a second portion abutting against the stud when the movable member is in the blocked position, so as to prevent the movement of the end of the plate relative to the stud in both longitudinal directions. In other words, in the blocked position, the displacement of the sliding end of the plate relative to the board is prevented, both to the front and to the rear.
This arrangement is of interest when, in its rest position, i.e. under the static load of the user, the platform is in an intermediate position relative to the board, i.e. it has the ability to slide either toward the front or toward the rear.
Advantageously, in practice, if the movable member can pivot relative to the platform, the mutually abutting zones of the stud and of the movable member are cylindrical. In this way, during pivoting of the movable member relative to the stud, the two cylindrical profiles of the stud and of the movable member slide relative to one another.
In practice, the movable member may be fitted in a housing provided for this purpose under the platform, which limits the overall height of the device.
According to another characteristic of the invention, the platform may also include return means interposed between the platform and the movable member. These said means are capable of pressing the movable member against the stud in a direction perpendicular to the plate. In other words, the return means are provided in order to maintain contact and interaction between the movable member and the stud in order to ensure, in particular, the permanent nature of blocking, particularly when the movable member abuts against the stud.
Advantageously, in practice, the platform may include at least one longitudinally elongate aperture inside which a point for anchoring on the board, such as, in particular, a screw, is capable of sliding. In this case, the characteristic stud is secured to the board by this anchoring point which may, for example, pass through a part of the front stud before being screwed inside the structure of the board.
According to another characteristic of the invention, the stud or movable member may have means for preventing the free displacement of the movable member, i.e. to hold the movable member either in the xe2x80x9cblockedxe2x80x9d position or in the xe2x80x9cfreexe2x80x9d position. In other words, the position of the movable member may be locked in order to prevent it being displaced unexpectedly during use.
In practice, these means for preventing the free displacement may be formed by bosses present on the stud and intended for interacting with at least one edge of the portion of the movable member abutting against said stud. In other words, these bosses form zones of excess thickness that the movable member has to surmount in order to pass from the free position to the blocked position, and vice versa. The effort needed to pass from one position to the other must require intervention on the part of the user and cannot be the result of mere vibrations.
In another embodiment, the means for preventing the free displacement of the movable member include a spring leaf integral with the stud interacting with a portion of the movable member. The two xe2x80x9cfreexe2x80x9d and xe2x80x9cblockedxe2x80x9d positions correspond to configurations in which the spring leaf is practically not under stress. On the other hand, in order to pass from one position to the other, it is necessary to exert a minimum effort which is sufficient to counter the effect of this spring leaf. This minimum effort is determined so that there is no unexpected displacement of the movable member.